Conventionally, industrial robots which perform automatic processing or assembly operations stop operation due to a failure of a main power supply in case of a power failure during automatic operation. After restoration of power, an operator has to restore operating conditions and discharge work-in-process. Consequently, a robot reset operation becomes complicated and requires time, resulting in reduced throughput of the production line.
Thus, a robot controlling apparatus has been proposed which automatically performs a reset action of a robot body when the main power supply is restored after a power failure (see PTL 1). The robot controlling apparatus memorizes a stop position of the robot body, state of a hand of the robot body, and the like if the robot body stops in the middle of an operation due to a power failure. When the main power supply is restored, the robot controlling apparatus reads a recovery program corresponding to a memorized state of the robot body out of multiple recovery programs. Next, the robot controlling apparatus returns the robot body to its initial state according to the read recovery program and them causes the robot body to resume operation.